Hydrocarbon oil conversion



May '14, 1935 E. F. NELSON 2,001,150

HYDROCARBON OIL CONVERSION Ffild May 9, 1928 KNT 'Patented May 14, 193s" UNITEDA STATES 2,001,150 mmnocAnoN on. CONVERSION Edwin F. Nelson,

Chicago, Ill., assignor to Universal Oil Products Company,

Chicago, lll.,

a corporation of South Dakota Application May 9, 1928, Serial No. 276,264 s claims. (ci. 19e-V58) The present invention relates to improvements in process and apparatus for hydrocarbon oil conversion, and refers more particularly to a process and apparatus especially adapted to strip from certain fractions, such as reux condensate, de-

sirable lighter ends which may be contained therein.

In hydrocarbon oil conversion processes it is propbsed to employ a fractionating element to separatethe sufficiently converted fractions from the insufficiently converted fractions. Although many of these fractionating 'elements' are highly efcient, few of them, if any, function perfectly, there generally always being a substantial q uantity of the suiiiciently converted fractions entrapped with the insuiiiciently converted fractions Which latter condense as reflux condensate.

Itis an object, therefore, of the present invention to provide a process and apparatus especially 20 v adapted to strip from the insuiciently converted fractions condensing as reflux condensate any of the sumciently converted fractio which may be entrapped therein.

lThe process briefly described comprises withdrawing from the system regulated quantities of the charging stock after it has been heated to a predetermined point and bringing it into direct and/or indirect contact with the reflux condensate in the fractionating element to heat and retherefrom substantial amounts of the sufficiently converted fractions contained therein.

The advantages of this method of stripping the reux condensate will 'be readily apparent to those skilled in the art for itaffords a simple, efficient and eective method of reboiling without the use of added equipment. Any of the conventional cracking apparatus may be easily altered to carry out the method with very little cost.

Other objects, features and advantages of the present invention will be more apparent from the following detailed description.

The single gure in the drawing is a diagrammatic side elevational view, `partly in vertical section, of apparatus in which the present invention may be carried out.

Referring more in detail to the'drawing, the raw oil or charging stock is drawn from a suitable 0 source throughA line I and forced by means of a pump 2 through the line 3 which lcommunicates with the lines 4 and 5 controlled respectively by valves 6 and '1, whereby upon regulation of the latter any regulated portion of the charging `5 stock may be introduced into the dephlegmator 8 trolled by valves it. Manholes il boil such reflux condensate to revaporize and strip l of, a regulated portion of the charging stock. The

and/or any regulated portion of the charging p stock may be introduced into the coil 9.

Assume for the purpose of illustration that all the charging stock is passed through the line B into the coil 9. The coil 9 may be mounted in a 5 suitable furnace I0 provided with burners H. While passing through the coil 9 the charging stock may be heated to a conversion and/or cracking temperature, flowing therefrom through transfer line l2, controlled by valve i3, discharging into the reaction and/or separating chamber M wherein the heated charges separate into vaporous and non-vaporous products of reaction, the latter comprising liquid. and/or solids. The residue may be withdrawn from the chamber it l5 through one or more of thedraw-oifs it, conmay be provided at the top and bottom of the chamber. The vaporous fractions pass out of the chamber" it through vapor line it, controlled by valve i9, and pass to the dephlegmator t, wherein they. undergo fractionation in the usual manner.`

The vapors which remain uncondensed after passing through the dephlegmator t pass out therefrom through the line 2t, controlled by valve 2l, thence4 through the -condenser M and` through line 23 controlled by valve M. Con. densed vapors and gases collect in the receiver 25 which is provided with gas relief line 2t, controlledby valve 2l, and with liquid draw-0E 2t, 30 controlled by valve 29.

Dephlegmation of the vapors may be assisted by introducing through the line t at the top of the dephlegmator 8, or at any other portion therereflux condensate formed, together with the unvaporized portion of the charging stock, collects in the bottom" of the dephlegmator and may be Withdrawn therefrom through the line controlled by yalve 3l, and directed by means of@ A pump 32 into the line 5 leading to the heating coil 9 as heretofore described.

As a feature of the present invention, one or y more lines 35, controlled by valves 36, may communicate with separate points of the heating coil 9. These lines 35 may be connected by means of a header 31 to the line 38, controlled by valve 39, which communicates with the lower portion of the dephlegmator 8, whereby regulatedquantitles of the heated oil passing through heating tube 9 maybe diverted and introduced into the dephlegmator and brought into direct or indirect contact with the reflux condensate therein. Since this heated oil is hotter than the reux condensate 55 Fthe latter will be heated by the former whereby lighter desirable fractions will be boiled out from the reux condensate, passing out through the line 20 as vapors, whereby they will be collected in the receiver 25. As the oil flows through the coil 9 its temperature is progressively increased, hence the temperature of the charging stock withdrawn from the coil 9 will vary according to the portion of the coil from which it is withdrawn.

By regulating at the same time the quantity of the charging stock withdrawn from the coil 9, a very close control over the heating of the reflux may be maintained. The charging stock so introduced into the dephlegmator 8 may be in the liquid and/or vapor phase, depending on the point of the coil from which it is withdrawn and the conditions of operation.

While I have shown the charging stock as being withdrawn intermediate the coil 9 it is to be understood that it may instead be withdrawn from the end thereof, or the transfer line I2. It is also to be understood that instead of introducing the heated charging stock into direct contact with the reflux condensate, the charging stock may be passed through a closed coil which is submerged in the reflux condensate.

The particular conditions of operation are, of course, left to the judgment of a skilled operator. These conditions of temperature and pressure will vary widely, depending upon the type of charging stock being used and the types of products desired. As an illustration, which is not to be construed in any way as a limitation of the invention, the oil passing through the heating coil 9 may be raised to a temperature of approximately 800 to 950 F., more or less, while being maintained under a superatmospheric pressure of from 25 to 200 lbs., more or less. Uniform pressure may be maintained throughout the system or differential pressures maintained on different parts of the system by obvious manipulation of the valve illustrated.

I claim as my invention:

1. A hydrocarbon oil cracking process which comprises passing the oil in a restricted stream through a heating coil wherein the oil is heated to cracking temperature, removing from the coil a portion of the oil passing therethrough and discharging the remainder thereof into a vapor separating zone, separately removing vapors and unvaporized oil from said zone and subjecting the former to dephlegmation to condense insuiciently cracked fractions thereof as reflux condensate, and re-boiling said re'flux condensate by admixing the same with said portion of the oil removed from said coil.

2. A hydrocarbon oil cracking process which comprises passing the oil in a restricted stream through a heating coil wherein the oil is heated to cracking temperature, removing from the coil a portion of the oil passing therethrough and discharging the remainder thereof into a vapor separating zone, separately removing vapors and unvaporized oil from said zone and subjecting the former to dephlegmation to condense insufflciently cracked fractionsthereof as reux condensate, reboiling said refiux condensate by admixture with said portion of the oil removed from said coil, and returning to the coil the unvaporized constituents of said portion of the oil.

3. A hydrocarbon oil cracking process" which comprises passing the oil in a restricted stream through a heating coil wherein the oil is heated to cracking temperature, removing from the coil 2,001,150 a portion of the oil passing therethrough and discharging the remainder thereof into a vapor separating zone, separately removing vapors and unvaporized oil from said zone and subjecting the former to dephlegmation to condense insuiiiciently cracked fractions thereof as reflux condensate, and re-boiling said reflux condensate by admixing the same with said portion of the oil removed from said coil, and returning the unvaporized portion of the resultant mixture to the coil for retreatment in the process.

4. In a hydrocarbon oil cracking process of the character wherein the oil is heated to cracking temperature by passage through a heating coil and thence introduced into a vapor separating zone for separation into vapors and residue and the vapors dephlegmated to condense insufiiciently cracked fractions thereof as reflux condensate, the improvement which comprises withdrawing from an intermediate point in the coil a portion of the oil passing therethrough while the remainder thereof is being directed through the rest of the coil and into said separating zone, and reboiling said reflux condensate by direct contact with said portion of the oil withdrawn from the coil.

5. In a hydrocarbon oil cracking process of the character wherein the oil is heated to cracking temperature by passage through a heating coil and thence introduced into a vapor separating zone for separation into vapors and residue and the vapors dephlegmated to condense. insufflciently cracked fractions thereof as reflux condensate, .the improvement which comprises withdrawing from an intermediate point in the coil a portion of the oil passing therethrough while the remainder thereof is being directed through the rest of the coil and into said separating zo'ne, and reboiling said reflux condensate by direct contact with said portion of the oil withdrawn from lthe coil, and returning the unvaporized portion of the resultant mixture to the coil for retreatment in the process.

6. A hydrocarbon oil cracking process which comprises heating the oil to cracking temperature while flowing through a heating coil, removing the oil from the coil in two separate streams, discharging one of said streams into a vapor separating zone and effecting a separation of vapors from unvaporized oil therein, passing the vapors to a dephlegmating zone and condensing insufficiently cracked fractions therein as reux condensate, and reboiling the reux condensate in said dephlegmating zone by admixture with the other of said streams whereby thelvapors evolved from the reflux condensate and from said other stream mingle with the vapors undergoing dephlegmation, and returning the unva-V porized portion of the reux condensate and the unvaporized portion of said other stream to the coil for further treatment in the process.

7. A hydrocarbon oil cracking process which comprises heating the oil to cracking temperature while iiowing through a heating coil, removing the oil from the coil in two separate streams, discharging one of said streams into a vapor separating 'zone and effecting a separation of vapors from unvaporized oil therein, passing the vapors to a dephlegmating zone'and condensing insuiliciently cracked fractions therein as reflux condensate, and reboiling the reux condensate in said dephlegmating zone by introducing the other of said streams into the lower portion of said dephlegmating zone to commingle with the reflux condensate therein whereby the vapors evolved from the reflux condensate mingle with the vapors undergoing dephlegmation. y

8 A hydrocarbon oil cracking process which comprises heating the oil to cracking temperature while owing through a heating coil, re-

`moving a first stream of oil from the/coil at a point intermediate the inlet and outlet thereof, removing the remainder of the oil as a second stream from the outlet of the coll and introducing thevsame to a vapor separating zone for separation into vapors and. unvaporized oil; passing the vapors to a dephlegmating zone and condensing insufciently cracked fractions therein as reux condensate, and reboiling the reux condensate in said dephlegmating zone by directl tion. 1, EDWIN F. NELSON. 

